In 3GPP (3rd Generation Partnership Project), LTE-A (LTE-Advanced) has been discussed as the next communication scheme of LTE (Long Term Evolution; (3rd Generation)) currently designed in the Rel-8 of 3GPP. In the LTE-A, it has been required to perform high rate communication and support a wide bandwidth (a 100 MHz band exceeding a 20 MHz band of LTE) as compared with the LTE.
However, it is difficult to ensure a continuous frequency band of a wide bandwidth for the LTE-A worldwide. Furthermore, it is preferable that the LTE-A be compatible with the LTE.
In this regard, there has been proposed carrier aggregation (CA) technology in which a plurality of carriers with a bandwidth of 20 MHz are collectively used for communication to ensure a bandwidth of 100 MHz at maximum and perform large capacity communication at a high speed. This CA technology was admitted as communication technology to be used in the LTE-A in 3GPP RAN 1#53b meeting (Non-Patent Document 1). In addition, in the CA technology, a carrier up to 20 MHz is called a component carrier (CC).
Meanwhile, the CA technology has been known as in the following Non-Patent Documents 2 and 3.
Non-Patent Document 2 discloses CA technology for a plurality of CCs with the same coverage which are transmitted from one base station. Furthermore, Non-Patent Document 2 discloses CA technology in which LTE non-compatible CCs to be defined in the LTE-A are considered, in addition to CCs defined in the LTE in relation to CCs, and technology in which directionality of a standard design for a synchronization method, system information, control information and the like has been suggested.
Furthermore, Non-Patent Document 3 discloses CA technology for LTE compatible CCs and LTE non-compatible CCs, and technology using the CA technology according to a communication traffic state of each cell.